Arrogant Body Language
Watch how the guy walks across the room and notice if he has an overly confident swagger.
If he puffs out his chest, widens his shoulders and walks with a blatantly laid back glide, he is exuding arrogance. Observe how he sits in a chair. If he places his feet wide apart and leans back in the chair he may be trying to convey that he is not bothered by or too cool for the situation. This is a sign of cockiness.
The way a guy talks to you is one of the best ways to detect cockiness.
If your conversations tend to be one-sided, with him doing most the talking, it is a sign of cockiness. If he continually brags about his life, such as where he has traveled, how quickly he was promoted at work, his connections to celebrities and his educational achievements; then he is probably cocky. Pay attention to how often he seems to genuinely care about your input and asks you questions about your life. If he doesn't engage with you in this way very often, it is likely that he is cocky.
Flashes Material Items
A guy who feels the need to frequently show off his wealth is overconfident and probably cocky.
Observe his behavior and notice if places a lot of emphasize on material items, such as his car, his boat and his clothing. Check to see if he ostentatiously wears extravagant rings, earrings and necklaces. A guy who has one or two of these items is not necessarily arrogant, but if his display of wealth appears over-the-top, then he probably is cocky.
A guy who frequently criticizes others is very likely to be cocky.
Pay attention to how often the guy puts others down, makes negative judgments about other people and openly criticizes someone for incompetence. For example, take note anytime he gets angry at a waiter or waitress for making a mistake with the order or he criticizes someone for their lack of knowledge on a particular topic. If these behaviors are common, he is probably cocky.